Hydraulic back-pressure valve.



flQLIGHTFOOT. 7 HYDRAULIC BACK PRESSURE VALVE.

APPLICATION FILED JAILQB, 1912.

1,045,715. mm Nov. 26, 1912.

onrrnn sra'rns PATENT canton;

CECIL LIGHTFOOT, OF

BUFFALO, NEW YORK, ASSIGNOR TO OXWELD ACETYLENE COMPANY, OF CHICAGO, ILLINOIS.

HYDRAULIC BACK-PRESSURE VALVE.

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Specification of Letters Patent.

- Patented Nov. 26, 1912.

Application filed January 26, 1912. Serial No. 673,605.

To all whom it may concern: I p v Be it known that I, Cnon. LIGHTFOOT, a

subject of KingGeorge V, of Buffalo, in the I p in hydraulic back-pressure valves, designed particularly for use in connection with gaspointed out in the claims.

blow-pipes using a mixture of gases drawn from independent-sources, theobject being to prevent a reversal of the flow of one gas into and toward the source of the other, and it consists in the parts. and combinations of parts as will be more fully described ,and

The accompanying drawing is a View in vertical section of one form of apparatus embodying my invention.

For the purpose of describing this inven-- tion, it will be assumed that one gas is oxygen underconsiderable pressure in a cylinder, and the othergasis acetylene under very low. pressure flowing from an acetylene generator, the two gases being employed together in a blow-pipe. I

1 represents a cylinder or tank, which, at the commencement of the Operation is filled with water up to the plug 2. This tank is provided with a cover 3 secured thereto by screws 4 or by other suitable fastening devices, a packing 5 being interposed to prevent the leakage of any gas.

' Formed integral with the cover 3, or secured thereto in any suit-able manner, are the three pipes 6, 7 and 8, the former of which terminates preferably in the plane of the cover, while the pipes 7 and 8 project down below the water level, the pipe 7 terminating in a perforated head or drum 9, the latter being in a plane below the lower end of ipe 8. The three pipes 6, 7 and 8 project a ove the cover, the pipe 6 being connected with the outlet pipe 6 the pipe 7 with the inlet pipe 7 and the pipe 8 with the vent pipe 8. The lower end of the seal pipe 8 is surrounded by a sleeve or short section of pipe 9 which extends. from approximately the plane of the normal water level in the cylinder l below the lower end of pipe 7, but is open at its bottom water.

Pipe 8 is of a length slightly greater than the height of a column of water sustained for the free entrance of by the pressure at which the acetylene gas is delivered to the tank, and asbefore explained is water sealed and opens at its upper end into vent pipe 8, which is connected in a plane below the vent opening with the U-shaped tube 10, which is provided at its free end with a filling funnel 11.

Cook 12 is interposed in a coupling between pipes 6 and 6, and cock 13 is-interposed between pipes 7 and 7 so that com: munication between these pipes 6 and 7 and the cylinder l may be cut off.

In the operation of the apparatus the cooks 13 and .12 are closed, the plug 2 removed, and water poured into the filling funnelfll until it fills the tank up to the openingclosed by plug 2.v Plug 2 is now re placed and cook 13 opened, thus permitting the acetylene gas from the generator to enter pipe 7 and tank 1 and force some of the water in the latter, into pipe 8, until the latter contains a column of water equal in height to a column of water that would be formed by the pressure of gas in the acetylene gas generator. In so doing the level of the water will be lowered in the tank by an amount corresponding to the volume of the column of water in pipe 8. Cook 12 should now be opened and the incoming gas from the generator will then bubble up through the waterand pass out through the outlet pipe 6 to the blow pipe.

Should any pressure be produced in th soutlet pipes 6 and 6 in excess of the pressure existing in pipe 7, the excess of pressure 1n pipe 6 and tank 1, will cause the wvater in tank 1 to flow up through pipe 8 and over into the U-shaped tube 10, which in time will overflow at 11, until enough water has been forced out of the tank to lower the level until the lower end of pipe 8 is no longer immersed, thus permitting the gas toescape through pipe 8 and vent 8* to the outer air.

As the lower end of inlet pipe is at a lower level than pipe 8, the inlet pipe will still be submerged after pipe 8 has been opened to the atmosphere, so that no gas, can by any possibility, pass back into delivery pipe 7, and as the U-shaped tube is also filled with water, none of the escaping gas can pass into the building in which the apparatus is placed, hence the U-shaped tube. acts both as a seal, and indicates that the gas is escaping through the rent. The pipe 9 surroumli-ng.tlte lower end of pipe 8, maii'itains the v vater around the latter in a quiet state, and prevents the bubbles of gas escaping from the head. or drum 9, from passing up through pipe 8 and breaking or interfering with the water seal therein.

it is a perforated battle plate located within tank 1 just slightly below the normal level of the water therein.

From the construction disclosed it is also evident that if a lower pressure or vacuum should be created in tank 1 due to a failure of acetylene gas supply, the water in pipe 8 wouldfall and permit air to enter through the vent.

Slight changes might be made in the general form and arrangement of the parts described without. departing from my invention, and hence I do not restrict myself to the precise details set forth but consider myself at liberty to make such slight changes and alterations as fairly fall within the spirit and scope of my invention.

Having fully described my invention what I claim. as new and desire tosecure by Let- I tors-Patent, is:

vent pipe and also below the lower end of the outlet pipe.

2; A hydraulic back pressure valve coin.

prising a tank having a water outlet located at the normal water level, means for etosmg said opening and a cover carrying. an inlet pipe, an outlet pipe and a combined seal and vent pipe, the latter terminating below the inner end of outlet pipe but above the lower pipe, and a sleeve open at its top and bottomv and surmounting the lower end of the combined seal and vent pipe.

t. A hydraulic back pressure valve comprising a closedtank, inlet and outlet pipes and a combined sealv and vent pipe communicating with said tank above the bottom of the latter, the said seal and vent pipe terminating below the lower end of the outlet pipe, but above the lower end of the inlet pipe, and a bent pipe connected with the combined vent and seal pipe at the upper end seal section of the latter and adapted to receive the overflow from the latter.

5. A hydraulic back pressure valve comprising a closed tanl-I, inlet and .outlet pipes and a combined seal and vent pipe communicating with said tank above the bottom of the latter the said seal. and vent pipe termi- 'nating below the lower end of the out-letpipe,

but above the lower end of the inlet pipe and an indicator pipe communicating with the combined vent and seal pipe atthe upper end of the sea-l section of said pipe, so as to receive the overflow from the'latter.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

CECIL LIGHTFOOT. Witnesses:

THOS. J. MATHEWS, J12, C. H. O. JENKINS. 

